The present invention relates to an assembly for the proximal end of a medical device, and, more particularly, a needle assembly that is operable when connected to a handle.
It is known in the art of medical devices that at least a portion of the device must be sterilized prior to being inserted into a patient. To facilitate the sterilization process, sterilization is sometimes performed prior to assembly of the medical device.
U.S. Pat. No. 5,429,138 to Jamshidi discloses a biopsy needle that is attachable to a handle by a threaded connector. The common practice prior to using the Jamshidi device is to sterilize both the needle and the handle, either as a complete unit or separately for later assembly by the operator or her assistant. U.S. Pat. Nos. 5,522,798 and 5,634,473 of Goldenberg et al. also discloses a biopsy needle that threadedly connects to a handle mechanism. In all of these designs, the handle mechanism remains external to the patient and does not require sterilization.
A common problem of each of the foregoing biopsy needle designs is that the connection of the needle to the handle requires that a threaded element be passed over the distal tip of the needle to secure the needle to the handle. This threaded connector must also be sterilized or else the sterility of the needle and the safety of the patient will be compromised. Further, the ordinary course of using a biopsy needle requires the operator to twist the needle within the patient and such manipulation could result in a loosening of the threaded connection between the needle and the handle.
The present invention resolves these and other problems by providing a snap- lock connection between the operative handle and the medical device.
In accordance with one aspect of the invention, a connector assembly for snap-connecting the proximal end of a medical device to a handle is disclosed. The assembly comprises a body that is rigidly attached to the proximal end of the medical device. A lever is attached to body and is resiliently biased towards a first position which engages the handle. A lock-tab projects from the lever in a direction generally away from the body and is shaped to be received in a lock-slot within the handle. Preferably, the lock-tab and handle are shaped to permit a snap-lock engagement of the handle and the body upon insertion of the body into the handle. This assembly can be used on a variety of medical devices and with a variety of handles.
In accordance with another aspect of the present invention, a needle assembly is disclosed which includes a hollow needle having a proximal end attached to the above described connector assembly for snap-lock engagement of the needle to the handle. A particular advantage of this construction is that the body at the proximal end of the needle can be securely engaged to a handle without the need for a threaded connector as in the above-described prior art designs. Further, the needle assembly can be provided in a sterile package and assembled to a handle without compromising the sterility of the working end of the needle prior to use.
According to a further aspect of the present invention, a biopsy needle kit is disclosed which includes a hollow needle having the above described connector assembly attached at a proximal end thereof and a handle having an aperture sized to receive the body at the proximal end of the needle. Further, the handle has lock-slots positioned within the aperture to receive the lock-tabs of the connector assembly. Upon insertion of the needle into the handle, the lever of the body is cammed toward the body until the lock-tab of the body aligns with the lock-slot of the handle at which moment the lever resiliently moves towards its rest position to lock the needle assembly to the handle. The operator can then use the needle to, for example, extract a biopsy sample, without concern for the sterility of the needle assembly as a result of the steps taken to connect the needle assembly to the handle.
In general terms, the invention provides a connector arrangement which securely engages two elements to one another without the need for manipulating the elements relative to one another (e.g., threading), yet with minimal risk of element separation. More particularly, through the use of camming surfaces, a secure engagement of the elements is automatically achieved by the inventive connector upon insertion of the connector, attached to a first element, into a second element.
The invention is described in connection with a preferred arrangement in which a medical device is provided with a connector assembly having a lever and a lock-tab projecting therefrom for engagement with a lock-slot within a handle. However, other arrangements are within the scope of the invention, including arrangements in which (1) the lock-slot is provided on the body (at the proximal end of the medical device) for engaging a cammable lock-tab on the handle; (2) a lever or cammable element provided on the body has a lock-slot which engages a corresponding lock-tab provided on the handle; or (3) a lever or cammable element provided on the handle has a lock-slot which engages a corresponding lock-tab provided on the body. In each arrangement, the handle and medical device positively engage one another in a reversible snap-lock interconnection, that is, in a snap-lock connection between the two which can be undone upon manually releasing the engagement therebetween.
These and other objects of the present invention will be appreciated from the following detailed description in conjunction with the detailed accompanying drawings.